AORTA— ARGUS 21 



reality but few of these birds have an outward resemblance to Shrikes, 

 Thrushes, or Wrens, and all belong to quite a different division of 

 Passeres. In 1847 Johannes Midler and Prof. Cabanis justly 

 placed them among their Clamatores, and subsequently Garrod 

 shewed their Mesomyodian structure. The Formicariida} are one 

 of the most characteristic Families of the Neotropical Region, 

 abounding in the forest-districts of its middle portion, becoming 

 less numerous in Central America, and still scarcer in the southern 

 parts, only just reaching the plains of La Plata. They are mostly 

 small birds of sober hue, some not bigger than Wrens ; but members 

 of the Genera Batara and Grallaria attain the stature of a Jay. The 

 last named of them has much the appearance of a Pitta — a distinct 

 group to which the name "Ant-Thrush" has also been applied. 

 As is the case with most South- American birds, scarcely anything is 

 known of their habits. The large genus Thamnophilus, containing 

 upwards of 50 species, is one of the most 

 important of the so-called "Bush-Shrikes," 

 and many of its members are remarkable 

 for the sexual diversity in plumage, that 

 of the cocks being black or black banded 

 with white, while that of the hens is 

 rufous ; but in some other groups the 

 black or black-and-white plumage is 



, 1 , 1 r\! j_i • Ant-Thrush (Thamnophilus). 



common to both sexes. Of this genus ^^^^er swainsonf) 



several species inhabit British Guiana, at 



least three occur in Trinidad, and one is found in Tobago, where it 

 is known as the Qua-qua or Cata-bird {Ann. N. H. xx. p. 331), their 

 presence in these two islands offering one of the many strong 

 proofs of their fauna belonging to that of continental South 

 America, since no member of the Family is found in the Antilles 

 proper. 



AORTA (adj. aortic), the principal Artery from which arise 

 the blood-vessels supplying the trunk, hind limbs, and viscera below 

 or behind the heart (see Vascular System). 



APTERYX, see Kiwi. 



ARCH^OPTERYX, see Fossil Birds. 



AREND, the Dutch for Eagle, but used by the colonists in 

 South Africa for the Bearded Vulture or Lammergeyer. 



ARGALA, Hindoo Harglla — said by Yule to be the K/yAa of 

 ^lian (xvi. 4) — a name of the Adjutant. 



ARGUS or ARGUS-PHEASANT, the name originally applied 

 in ornithology to the extraordinary and beautiful birds of the 

 Malay Peninsula, Siam, and Borneo, Avhich are not distantly related 

 to the Peacock ; but by English sportsmen in India commonly 



